|Title||Synthetic and mechanistic aspects of a new method for ruthenium-metalation of porphyrins and Schiff-bases|
|Publication Type||Journal Article|
|Year of Publication||2008|
|Authors||Reboucas, JS, Cheu, ELS, Ware, CJ, James, BR, Skov, KA|
|Type of Article||Review|
|Keywords||3-COMPONENT COUPLING REACTION, AQUEOUS-SOLUTION, CARBON-MONOXIDE, CATALYTIC-PROPERTIES, CRYSTAL-STRUCTURE, ELECTROCHEMICAL PROPERTIES, ORGANIC TRANSFORMATIONS, OXIDATION REACTION, REVERSIBLE BINDING, X-RAY-STRUCTURE|
A new method is presented for metalation of a wide range of free-base, neutral, cationic, and anionic porphyrins in refluxing dimethylformamide (DMF) using an easily prepared [Ru(DMF)(6)](OTf)(3) complex, and comparisons are made with the more familiar metalation procedure using Ru-3(CO)(12). Both procedures generate Ru-II(porp)(CO)L complexes (L = solvent); use of the Ru-III-triflate precursor gives yields comparable to, or greater than, those obtained with the carbonyl, and generates no Ru-chlorin impurities. Mechanistic studies on the meso-tetraphenylporphyrin system reveal that the DMF furnishes the CO, which in the presence of essential water reduces the metal, and metalation likely occurs via a Ru-II-CO species. Corresponding metalation of tetradentate Schiff-bases gives trans-[Ru-III(Schiff-base)(DMF)(2)]OTf complexes in yields of similar to 50%, a limitation being the accompanying hydrolysis of the Schiff-base through the presence of trace water.
|URL||<Go to ISI>://000258709500057|